The present invention relates to an arrangement for actuating controllable elements, for example light-emitting diodes in an information display.
In many cases today, displays with light-emitting diodes (LED's) are used to display alphanumeric symbols and images with relatively low definition. These arrangements, which are called LED displays, have a number of advantages such as their low operating voltage, their rapid response time, the possibility of multiplex operation, a broad range of operating temperature, robustness and a long life span. The number of LED's required depends on the respective application. For a digit display (0-9) including a decimal point, for example, 8 LED's are required, 14-35 LED's are required for letter characters, 100 LED's are required for strip display with 1% definition and more than 1,000 LED's are required for a viewing screen.
A relatively large number of supply lines is generally required to control or trigger the LED's. If, for example, the cathodes of all of the LED's are connected together and if each diode is individually controlled, n supply lines are required to control n-1 diodes. In addition, there is the system of so-called matrix wiring which can control n.sup.2 /4 diodes with n supply lines.
Although matrix wiring reduces the number of supply lines, a relatively large number of supply lines is still required if there are very many LED's. The large number of supply lines required in many cases represents a serious problem in implementing diode displays. Moreover, in matrix wiring lines always cross and this is not advantageous.